Facile synthesis of super-thermal insulating polyimide aerogel-like films

Thermal superinsulation materials play a key role in reducing energy consumption. In this article, flexible polyimide aerogel-like films are developed by a facile non-solvent-induced phase separation combined with ambient drying method. The pore structure and insulation properties are well controlled by changing the compositions of the coagulation bath. Polyimide films with macro-nano hierarchical pore structure and uniform nanopores are prepared by adjusting the content of water and alcohol as the non-solvent. The relationship between the insulation performance and textured structure of polyimide was studied. After optimization, the produced film achieved a low thermal conductivity of 0.019 W⋅m^-1·K^-1 but good tensile strength of 89.6 MPa, compared favorably with literature results. Hence, this article demonstrates that application of the facile phase inversion method to prepare porous polymers can be expanded from desalination or gas separation fields to insulation for energy-saving purposes.